Activities of glycogen phosphorylase, alanine aminotransferase and aspartate aminotransferase in adult worms ofLitomosoides cariniirecovered from pyridoxine deficient cotton rats (Sigmodon hispidus)

Abstract

This paper demonstrates that the activities of glycogen phosphorylase (GP), alanine aminotransferase (ALT) and aspartate aminotransferase (AST) are reduced in adult worms of the filarial nematode Litomosoides carinii recovered from pyridoxine-deficient cotton rats when compared to worms recovered from pyridoxine-sufficient controls. GP, ALT and AST activities were determined in adult worms L. carinii recovered from cotton rat hosts over a 20-week experimental period. Activities of GP, ALT and AST in the parasite showed a direct correlation with the dietary pyridoxine intake of their host. Throughout the experiment, enzyme activities were significantly lower (P < 0.001) in worms from rats fed a pyridoxine-free diet ad libitum that in worms from rats fed either a stock colony diet, a pyridoxine-free diet ad libitum with daily supplementation of 100 micrograms pyridoxine or limited amounts of pyridoxine-free diet with daily supplementation of 100 micrograms pyridoxine. The lower than normal activity of GP, ALT, AST and other enzymes dependent on the biologically active derivative of pyridoxine, the coenzyme pyridoxal-5-phosphate (PLP), interferes with the protein, carbohydrate and lipid metabolism of L. carinii and may in part cause the reduced establishment, development and growth of the parasite in pyridoxine-deficient hosts.

Glycogen catabolism enzymes and protein fractions in the third and fourth larval stages ofAnisakis simplex

“…Active in a near-neutral medium, it was very sensitive to thermal effects and protected by the substrate (table 4, figs 4 and 5). Similarly to phosphorylases in other nematodes, Ascaris suum and Litomosoides carinii , it was activated by ATP and pyridoxal phosphate (Donahue et al , 1981; Yacoub et al , 1983; Beg et al , 1996). Caffeine activation of the enzyme (table 4) suggests that glycogen phosphorylase activity in L3 is controlled in a typical way, by the cAMP level, whereas, some properties of the enzyme from L4 were not typical for glycogen phosphorylases, e.g.…”

An aspartate aminotransferase of Wolbachia endobacteria from Onchocerca volvulus is recognized by IgG1 antibodies from residents of endemic areas

“…Animal AspATs of the subclass Ia have cytosolic and mitochondrial forms and are functionally active as dimers. In filarial parasites, amino acids can be efficiently used in energy generating pathways in which AspAT is involved (Davies and Ko¨hler 1990) and homogenates of filarial parasites have considerable AspAT activity (Beg et al 1996). The cytoplasmatic AspATs of subclass Ia from B. malayi, Caenorhabditis elegans Fig.…”